Danny Mullen returns up front for St Mirren having dropped to the bench at Tannadice after the birth of his daughter the previous evening.

Ryan Flynn, who had been a doubt for the first leg, drops to the bench.

Centre-half Gary MacKenzie looked like he was struggling at the end of Thursday's game and thought he had broken a wrist but has recovered to start.

Forward Simeon Jackson and on-loan Blackburn Rovers midfielder Brad Lyons miss out again.

Image source, SNS

As expected, on-loan Aalborg striker Pavol Safronko, who is the club's top scorer this season, returns to the United starting line-up in place of Osman Sow.

Sow was not only ineffectual but picked up a knock in the first leg, as did Peter Pawlett - and the former Aberdeen midfielder's place goes to defender Callum Booth.

Calum Butcher, the midfielder who was sent off in United's 2-1 win over St Mirren in the Scottish Cup in February, is back on the bench after the groin injury that forced him to miss the first leg.

Image source, SNS

Just a reminder of the combatants' contrasting routes to the play-off final.

St Mirren were involved a three-way battle to avoid relegation from the top flight.

Their good end-of-season form lifted them above Dundee, but they fell short of catching Hamilton Academical.

United were beaten to the Championship title by Ross County before the runners-up went on to beat third-top Inverness Caledonian Thistle in the two-leg semi-final.

Image source, SNS

Richard Winton
BBC Sport at Simple Digital Arena

The pockets of supporters already milling around the Simple Digital Arena are being buffeted by swirling wind and squally showers. Given the ground is quite open, it's going to make for tricky playing conditions unless it passes.

There was a healthy crowd of 11,062 at Tannadice for Thursday's first leg and now St Mirren have revealed that today's reverse fixture is their first-ever 8,000 sell-out.

The highest previous attendance at what is now called the Simple Digital Arena was their first-ever fixture there in January 2009, when 7,542 were there for the Premiership visit of Kilmarnock.

Both managers have been appealing to their fans to cheer them on to victory in the play-off.

St Mirren: Hladky, MacKenzie, Baird, Popescu, P McGinn, S McGinn, Hodson, Magennis, McAllister, Cooke, Mullen.

Substitutes: Holmes, Ferdinand, Muzek, Erhahon, MacPherson, Flynn, Nazon.

Dundee United: Siegrist, Booth, Reynolds, Watson, Robson, Bouhenna, Harkes, Connolly, McMullan, Clark, Safranko.

Substitutes: Laidlaw, Frans, Sow, Stanton, Butcher, C Smith, Pawlett.

For Dundee United's Robbie Neilson, it's all about "who has the biggest cajones".

It is nothing to do with the art of persuasion as the manager wasn't using it in the English sense but the Spanish one, which has been recently adopted in football parlance to refer to bravery that comes from large testicles.

It was a scrappy, nervy first leg that ended goalless at Tannadice on Thursday evening.

Live coverage of the build-up to today's final has just started on BBC Radio Scotland, both on FM and MW.

Richard Gordon's guests are former Dundee managers Neil McCann and Jim Duffy, with match commentary from Alasdair Lamont. Reporter Chick Young is trackside.

Image source, SNS

It might be seen by many as a case of "after the Lord Mayor's show", but not for fans of St Mirren and Dundee United.

To them, today's Premiership Play-off final second leg is every bit as important as Celtic's historic completion of the "treble treble", the Glasgow side having beaten Hearts in yesterday's Scottish Cup climax at Hampden.

Will St Mirren retain their place in the top flight for a second season, or will Dundee United end their three-year exile from the Premiership?

Stay with us for the build-up, live commentary and post-match reaction from the Simple Digital Arena.

Image source, SNS